fromFetch will not abort fetch request and trigger finalize operator when built in Mac or Linux (WSL in Win10)

[kambing86]

Bug Report

Current Behavior
fromFetch is not able to abort the fetch request for subscription1, check the Network tab in Chrome's Developer Tool

another bug is the finalize operator will not be triggered for subscription2 when it's aborted

it only happens when built in Mac / WSL in Win 10
but it is running totally fine in codesandbox

Reproduction
clone github repo, and run yarn && yarn start
https://github.com/kambing86/npm-explorer/tree/feat/use-fromFetch
https://github.com/kambing86/test-from-fetch

but it is running totally fine in
https://codesandbox.io/s/github/kambing86/npm-explorer/tree/feat/use-fromFetch
https://codesandbox.io/embed/test-fromfetch-3x463
https://codesandbox.io/s/github/kambing86/test-from-fetch

Expected behavior
When unsubscribe is called, the fromFetch should abort the fetch if it is not resolved, finalize operator should be triggered

Environment

• Runtime: Node 10 / 12, Chrome 74
• RxJS version: 6.5.2
• (If bug is related) Loader, build configuration: create-react-app
• built in macOS High Sierra / WSL in Windows10

Additional context/Screenshots
check the captured video here
https://youtu.be/ZaMm_n1K4Y8
https://youtu.be/PYt3MJ_tBNQ
https://youtu.be/CdqvooTDC0g

edit: use simpler repo to reproduce, will only happen if it's used in mergeMap operator

edit 27/6/2019: uploaded new video, localhost built in windows using node v10.16.0

edit 28/8/2019: added finalize operator and found a new bug

edit 3/9/2019: if I changed to use

import { fromFetch } from "rxjs/_esm5/fetch";

then everything works fine

[kambing86]

previous discussion in #4744

[kambing86]

should be fixed by this PR #5001